/*
 * Copyright (c) 2011, Nikolaus Moll
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * * Neither the name of the gradecalculator.net nor the
 *   names of its contributors may be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */
package net.gradecalculator.core;

import java.io.File;
import java.io.FileFilter;
import java.util.HashMap;

import net.gradecalculator.plugin.grade.interfaces.IGradeFactory;
import net.gradecalculator.plugin.loader.PluginLoader;
import net.gradecalculator.plugin.loader.exceptions.PluginException;

public final class GradeFactoryUtil {
	private static GradeFactoryUtil instance = null;
	private static String pluginsRoot = "plugins/grades/";
	private final HashMap<String, IGradeFactory> factories;
	private final HashMap<String, File> pluginMap;
	
	private GradeFactoryUtil()
	{
		factories = new HashMap<String, IGradeFactory>();

		pluginMap = new HashMap<String, File>();

		final File root = new File(pluginsRoot);
		final File[] plugins = root.listFiles(new FileFilter() {
			@Override
			public boolean accept(final File pathname) {
				if (pathname.isDirectory()) {
					return false;
				}
				return pathname.getAbsolutePath().endsWith(".jar");
			}
		});

		final String resource = "importplugin";
		for (File plugin : plugins) {
			try {
				final IGradeFactory factory = (IGradeFactory)PluginLoader.getPluginByResource(plugin, resource);
				pluginMap.put(factory.getCountryCode(), plugin);
				//CHECKSTYLE:OFF
			} catch (final PluginException e) {
				// do something...
				//CHECKSTYLE:ON
			}
		}
	}
	
	public static GradeFactoryUtil getInstance()
	{
		if (instance == null) {
			instance = new GradeFactoryUtil();
		}
		
		return instance;
	}
	
	public static void setPluginsRoot(final String root)
	{
		pluginsRoot = root;
		instance = null;
	}
	
	public IGradeFactory getFab(final String cc)
	{
		if (!factories.containsKey(cc)) {
			factories.put(cc, getPlugin(cc));
		}
		
		return factories.get(cc);
	}
	
	public void registerFactory(final IGradeFactory fab)
	{
		if (factories.containsKey(fab.getCountryCode())) {
			factories.remove(fab.getCountryCode());
		}
		
		factories.put(fab.getCountryCode(), fab);
	}

	private IGradeFactory getPlugin(final String cc)
	{
		if (!pluginMap.containsKey(cc)) {
			throw new PluginException("No Plugin for Country Code " + cc);
		}
		
		final String resource = "importplugin";
		return (IGradeFactory)PluginLoader.getPluginByResource(pluginMap.get(cc), resource);
	}

	public boolean hasFactory(final String countryCode) {
		try {
			return getFab(countryCode) != null;
		} catch (final PluginException e) {
			return false;
		}
	}
}
